Muons forms from decay of pions. There are different pions and ways of decays but some without gamma, for example Pi+=U`+ neutrino.
The Pions are involved in nuklear reactions as proton neutron exchange. _https://en.wikipedia.org/wiki/Pion_ The Muons in Holmlids measurements may come from Pion decay. And the Muons must be an essential part in the LENR reactions. I had Holmlid as lecturer in physical chemistry and thermodynamics long time ago.
